2009 Goshen County tornado
In the afternoon hours of June 5, 2009, a well-documented tornado moved across Goshen County, located in the state of Wyoming. The tornado was observed by hundreds of experimental radar instruments, and the event formed the pinnacle of the VORTEX projects, which aimed to document the formation and lifecycle of a tornado. The tornado and the observations of it were heavily studied by meteorologists in the following years, and footage of the tornado has been featured on several national television networks, including The Weather Channel.
Tornado summary
On the afternoon of June 5, a large tornado was observed by researchers with the VORTEX 2 tornado research project in Goshen County, Wyoming, with the entire life cycle of the tornado being broadcast live on The Weather Channel as part of their coverage of the VORTEX2 project. The tornado was on the ground for approximately 25 minutes and became rain-wrapped at one point, eventually roping out and dissipating. The tornado stayed in open rural areas and damaged only a few trees and telephone poles, leading to its rating of EF2 on the Enhanced Fujita scale. This tornado was also featured on an episode of the Discovery Channel series Storm Chasers, wherein the TIV 2 and the SRV Dominator both managed to penetrate the tornado with TIV 2 filming IMAX footage from inside the funnel.
Formation
Doppler weather radar positioned near the now-developed tornado recorded a rapid intensification over a period of three minutes, from 4:04 to 4:08. A decrease in convergence to the north of the tornado was also noted at around the same time.
Documentation
Prior observation preparations
In the hours leading up to the tornado, multiple researchers working with the VORTEX2 team set up numerous instruments along U.S. Highway 85, including a doppler weather radar. By the time all of the instruments were set up, the hook echo of the supercell was located to the southwest. The Doppler radar was activated a minute later, and began to detect a mesocyclone, and several minutes later convergence lines were also detected.
Observations
A Doppler on Wheels observed the entire lifecycle of the tornado in Goshen County, Wyoming. The radar also observed a peak wind speed of at above the ground level. However, these winds occurred over open land, and the tornado was only rated an EF2 based on the damage observed.